JP2024114160A - Ultrasonic bonding equipment - Google Patents

Abstract

To provide an ultrasonic welding device that can improve the welding of individual strands when converting a core wire made by bundling a plurality of strands into a single strand.SOLUTION: An ultrasonic welding device 1 includes a pressure member 12 and a vibration member 13 that are arranged opposite to each other in a height direction Z and holds an exposed core wire part W1a in the height direction Z, apply ultrasonic vibrations to the exposed core wire part W1a to vibrate it in an axial direction X to weld strands W11 together. The vibrating member 13 has a plurality of partitioned areas 22, 23 in which a vibrating surface 21 is partitioned along a width direction Y with a partition width L corresponding to an outer diameter S of the wire W11. In the plurality of compartmentalized areas 22, 23, a frictional force that acts due to contact with the strands W11 at the exposed core part W1a is alternately and relatively different along the width direction Y.SELECTED DRAWING: Figure 5

Description

The present invention relates to an ultrasonic bonding device.

When manufacturing electric wires with terminals, when a crimp terminal is crimped onto an electric wire having a core wire made of bundled strands of wires, the core wire is ultrasonically bonded before the terminal is crimped using an ultrasonic bonding device in order to efficiently destroy the oxide film formed on the surface of the strands and ensure electrical conductivity between the strands.

For example, Patent Document 1 proposes an ultrasonic bonding method in which, with the core wire restricted to a bonding width, pressure is applied in the height direction of the core wire to ultrasonically bond each strand to each other and form an integral flat plate.

JP 2004-95293 A

In conventional ultrasonic bonding devices, ultrasonic vibrations propagate in the height direction from the horn to the anvil, causing the wires to slide against each other in the height direction and bond adjacent wires to each other. On the other hand, in conventional ultrasonic bonding devices, the wires do not slide against each other in the width direction, which is perpendicular to the height direction, so there is a risk that the wires may not be bonded sufficiently in the width direction, leaving room for improvement.

The present invention aims to provide an ultrasonic joining device that can improve the joining of wires when a core wire made of multiple bundled wires is joined together into a single wire.

In order to achieve the above object, the ultrasonic bonding device according to the present invention is provided with a processing device for forming a single wire portion by solidifying the multiple wires in the exposed core portion of an electric wire having an insulating coating that covers the core wire with the end of the core wire exposed as an exposed core portion, the processing device including a pair of holding members that are arranged opposite to each other in a width direction perpendicular to the axial direction and that hold the exposed core portion in the width direction, and a pair of holding members that are arranged opposite to each other in a height direction perpendicular to the axial direction and that hold the exposed core portion in the height direction and that hold the exposed core portion in the height direction. and a pressure member and a vibration member that apply ultrasonic vibrations to the exposed core wire to vibrate it in the axial direction and join the wires together. The vibration member has a vibration surface that faces the exposed core wire in the height direction when the exposed core wire is clamped in the height direction by the vibration member and the pressure member, the vibration surface contacts the exposed core wire in the clamped state, and has a plurality of partition areas that are partitioned along the width direction with a partition width according to the outer diameter of the wire, and the frictional forces acting due to contact between the exposed core wire and the wire in the exposed core wire part are relatively different from each other along the width direction.

The ultrasonic joining device according to the present invention has the effect of improving the joining of the strands when a core wire made of multiple strands bundled together is joined to a single strand.

FIG. 1 is a diagram illustrating a schematic diagram of a processing device of an ultrasonic bonding apparatus according to an embodiment. FIG. 2 is a schematic diagram showing an electric wire processed by the processing apparatus of FIG. FIG. 3 is a schematic diagram of the processing apparatus of FIG. FIG. 4 is a schematic diagram showing a vibration surface of a vibration member in the processing apparatus of FIG. FIG. 5 is a schematic diagram showing the cross section taken along line AA of FIG. FIG. 6 is a schematic diagram showing the cross section taken along line BB shown in FIG. FIG. 7 is a schematic cross-sectional view of a vibration member according to a modified example of the embodiment.

The following describes in detail the embodiments of the present invention with reference to the drawings. Note that the present invention is not limited to the following embodiments. In other words, the components in the following embodiments include those that a person skilled in the art would easily imagine or that are substantially the same, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention.

[Embodiment]
First, an electric wire W processed by an ultrasonic bonding device 1 according to an embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 is a view of a processing device 2, which is a main part of the ultrasonic bonding device 1, viewed from the width direction Y, and shows a processed state of the electric wire W. Fig. 2 shows the appearance of the electric wire W that has been single-wired by the processing device 2.

For convenience, in the following description, of the illustrated X, Y, and Z directions, the X direction will be referred to as the "axial direction X", the Y direction will be referred to as the "width direction Y", and the Z direction will be referred to as the "height direction Z". The axial direction X, width direction Y, and height direction Z are mutually orthogonal. The axial direction X corresponds to the direction along the axis O of the electric wire W. The width direction Y and height direction Z are included in the directions orthogonal to the axial direction X. One side of the height direction Z will be referred to as the "upper side Z1" and the other side as the "lower side Z2".

The electric wire W in the embodiment will be described. The electric wire W is applied to, for example, a wire harness used in a vehicle. Here, the wire harness is, for example, a bundle of multiple electric wires W used for power supply and signal communication to connect each device mounted on the vehicle, and is connected to each device by a connector or the like.

As shown in Figs. 1 and 2, the electric wire W is composed of a conductive linear core wire W1 and an insulating coating W2 that is insulating and covers the outside of the core wire W1. The electric wire W is an insulated electric wire in which the core wire W1 is coated with the insulating coating W2. The electric wire W is generally flexible, but is not limited to this.

The electric wire W extends, for example, along an axis O shown in FIG. 2, and is formed so as to extend with approximately the same diameter in an axial direction X along the axis O. The electric wire W is formed so that its cross-sectional shape in a direction perpendicular to the axial direction X is circular.

The core wire W1 is, for example, a bundle of wires W11 made of a conductive metal, such as aluminum, aluminum alloy, copper, copper alloy, etc. The core wire W1 may be a twisted core wire made by twisting together a plurality of wires W11. Each wire W11 has a circular cross-sectional shape in a direction perpendicular to the axial direction X (see FIG. 5). The outer diameter S of the wires W11 is the same for the plurality of wires W11. In the electric wire W of the embodiment, the insulating coating W2 is stripped off at least one end in the axial direction X, and the core wire W1 is exposed from the end of the insulating coating W2 to form the exposed core wire portion W1a. The exposed core wire portion W1a has a circular cross-sectional shape in a direction perpendicular to the axial direction X, like the core wire W1. As shown in FIG. 2, the exposed core wire portion W1a has a single-wire portion W1b in which the plurality of wires W11 in the exposed core wire portion W1a are solidified into a single wire. For example, a crimp terminal (not shown) is crimped to the electric wire W near the end of the insulating coating W2 and to the single-wire portion W1b.

The single-wired portion W1b is, for example, a portion processed by the processing device 2 of the ultrasonic joining device 1. The single-wired portion W1b is formed in a columnar shape along the axial direction X, and unlike the core wire W1, has a rectangular cross-sectional shape in a direction perpendicular to the axial direction X.

The insulating coating W2 is formed, for example, by extrusion molding an insulating resin material (such as PP (polypropylene), PVC (polyvinyl chloride), cross-linked PE (polyethylene), etc., appropriately selected taking into consideration abrasion resistance, chemical resistance, heat resistance, etc.). The insulating coating W2 is formed so that its cross-sectional shape in the direction perpendicular to the axial direction X is approximately annular along the circumferential direction.

Next, the ultrasonic bonding device 1 will be described with reference to Figs. 1, 2, and 3 to 6. Fig. 3 is a view of the processing device 2 of the ultrasonic bonding device 1 shown in Fig. 1 as viewed from the axial direction X, and shows the processing state of the single-wire portion W1b. For convenience, the outer diameter of the wire W11 shown in Fig. 3 is enlarged, and the cross-sectional shape as viewed from the axial direction X remains circular. Fig. 4 is a schematic diagram of the excitation surface 21 of the excitation member 13 in the processing device 2. Fig. 5 is a schematic diagram of the cross section of the excitation surface 21 as viewed from the axial direction X. Fig. 6 is a schematic diagram of the cross section of the excitation surface 21 as viewed from the width direction Y.

The ultrasonic joining device 1 includes a processing device 2. The processing device 2, for example, forms a single-wire portion W1b by solidifying a plurality of strands W11 that constitute the exposed core portion W1a of one electric wire W. The processing device 2 has a pair of holding members 11, a pressure member 12, and a vibration member 13, which form the single-wire portion W1b. As shown in FIG. 3, the pair of holding members 11, pressure member 12, and vibration member 13 are arranged opposite each other in the width direction Y and the height direction. The pair of holding members 11, pressure member 12, and vibration member 13 form an accommodation space 15 for accommodating the exposed core portion W1a inside. Note that the ultrasonic joining device 1 shown in the figure does not include support members that support the pair of holding members 11, pressure member 12, and vibration member 13.

The pair of holding members 11 are arranged opposite each other in the width direction Y and clamp the exposed core portion W1a in the width direction Y. The pair of holding members 11 form both end faces in the width direction Y of the single-wire portion W1b while clamping the exposed core portion W1a in the width direction Y. The pair of holding members 11 are fixed in their respective positions in the width direction Y.

The pressure member 12 and the vibration member 13 are arranged opposite each other in the height direction Z, and clamp the exposed core wire portion W1a in the height direction Z. With the exposed core wire portion W1a clamped in the height direction Z, the pressure member 12 and the vibration member 13 apply ultrasonic vibrations to the exposed core wire portion W1a, vibrating it in the axial direction X along the vibration direction shown in FIG. 1, and ultrasonically joining the strands W11 together to form a single wire. The vibration member 13 is fixed in position, but the pressure member 12 is configured to be movable in the height direction Z when processing the exposed core wire portion W1a.

The pressure member 12 is a so-called anvil, and when the vibration member 13 and pressure member 12 are in a clamped state in which the exposed core wire portion W1a is clamped in the height direction Z, pressure is applied to the exposed core wire portion W1a in the height direction Z from the upper side Z1 to the lower side Z2.

The vibration member 13 is a so-called horn, and when the vibration member 13 and the pressure member 12 are in a clamped state in which they clamp the exposed core wire portion W1a in the height direction Z, they vibrate in the axial direction X to apply ultrasonic vibrations to the exposed core wire portion W1a from the lower side Z2 to the upper side Z1.

As shown in Figures 3 and 4, the vibration member 13 is formed on the storage space 15 side and has a vibration surface 21 that faces the pressure member 12 in the height direction Z. The vibration surface 21 contacts the exposed core portion W1a in a clamping state in which the vibration member 13 and the pressure member 12 clamp the exposed core portion W1a in the height direction Z.

5, the vibration surface 21 has a plurality of partitioned regions 22, 23 partitioned along the width direction Y by a partition width L corresponding to the outer diameter S of the wire W11 in a cross section viewed from the axial direction X of the vibration member 13. The partitioned regions 22, 23 are alternately formed along the width direction Y on the surface of the vibration surface 21 with which the exposed core wire portion W1a contacts. The partitioned regions 22, 23 in the embodiment have the same partition width L in the width direction Y. The frictional forces acting on the exposed core wire portion W1a and the wire W11 in the plurality of partitioned regions 22, 23 are alternately different from each other along the width direction Y. The partitioned regions 22, 23 adjacent to each other in the width direction Y are formed, for example, so that the contact areas T1, T2 with the wire W11 are the same. In addition, the partitioned regions 22, 23 adjacent to each other in the width direction Y are formed to have different surface roughness from each other by processing such as polishing or sandblasting, and thus have different friction coefficients.

As shown in Figs. 4 and 6, the vibration surface 21 has a plurality of convex portions 24 that are continuous along the axial direction X in a cross section viewed from the width direction Y of the vibration member 13. All of the plurality of convex portions 24 are tapered toward the upper side Z1 in the height direction Z, have the same height in the height direction Z, and have the same spacing P between their apexes in the axial direction X. The plurality of convex portions 24 are formed, for example, in an approximately central portion of the vibration surface 21 in the axial direction X, but are not limited thereto. The plurality of convex portions 24 are formed in the partitioned regions 22 and 23 adjacent to each other in the width direction Y.

Each partition area 22, 23 has the same partition width L in the width direction Y, but it is preferable that the partition width L is such that the outer diameter S of the wire W11 ≦ the partition width L ≦ the outer diameter R/2 of the exposed core wire portion W1a, depending on the outer diameter S of the wire W11 and the outer diameter of the exposed core wire portion W1a.

As described above, the ultrasonic joining device 1 according to the embodiment includes a processing device 2 arranged opposite to each other in the height direction Z, a pressure member 12 and a vibration member 13 that clamp one exposed core wire portion W1a in the height direction Z and apply ultrasonic vibrations to the exposed core wire portion W1a to vibrate it in the axial direction X and join the wires W11 together. The vibration member 13 has a vibration surface 21 having a plurality of partition areas 22, 23 partitioned along the width direction Y by a partition width L corresponding to the outer diameter S of the wires W11. The frictional forces acting on the exposed core wire portion W1a in contact with the wires W11 in the plurality of partition areas 22, 23 are relatively different from each other alternately along the width direction Y.

The ultrasonic joining device 1 applies ultrasonic vibrations to the exposed core wire portion W1a contained in the accommodation space 15 in a vibration direction along the axial direction X by the vibration member 13, so that the wires W11 that face each other in the height direction Z in the exposed core wire portion W1a slide against each other due to the ultrasonic vibrations, and are joined to each other. On the other hand, in the exposed core wire portion W1a, the wires W11 that face each other in the width direction Y in the exposed core wire portion W1a do not slide easily against each other, so there is a risk that the joining between the multiple wires W11 in the width direction Y is not sufficiently performed.

Therefore, for example, if the frictional force of the partition area 22 is made relatively small with respect to the partition area 23, the wires W11 in contact with the partition area 23 vibrate together with the vibrating member 13 during vibration, but the wires W11 in contact with the partition area 22 vibrate out of alignment with the vibrating member 13, causing the wires W11 adjacent in the width direction Y to slide against each other in the height direction Z. As a result, compared to conventional devices in which the frictional force acting due to contact between the vibrating surface 21 and the wires W11 is constant, the ultrasonic joining device 1 allows the wires W11 along the width direction Y to slide against each other, improving the joining between the wires W11 in the width direction Y and improving the joining between the wires W11 when a core wire W1 formed by bundling multiple wires W11 is made into a single wire.

In addition, in the ultrasonic bonding device 1 according to the embodiment, it is preferable that the partition width of the partition areas 22, 23 on the vibration surface 21 is such that the outer diameter S of the wire W11 ≦ the partition width L ≦ the outer diameter R/2 of the exposed core wire portion W1a. This makes it possible for the ultrasonic bonding device 1 to easily create a situation in which, when the exposed core wire portion W1a is vibrated, the wire W11 in contact with the partition area 23 vibrates together with the vibration member 13, but the wire W11 in contact with the partition area 22 vibrates out of alignment with the vibration member 13.

In addition, in the ultrasonic bonding device 1 according to the embodiment, the partitioned regions 22, 23 adjacent to each other in the width direction Y are formed to have different surface roughnesses, which results in different friction coefficients. As a result, the frictional forces acting on the partitioned regions 22, 23 adjacent to each other in the width direction Y due to contact with the wires W11 at the exposed core wire portion W1a can be made to be relatively different from each other alternately along the width direction Y. In this way, the ultrasonic bonding device 1 can improve the bonding between the multiple wires W11 in the width direction Y, and improve the bonding between the wires W11 when the core wire W1, which is a bundle of multiple wires W11, is made into a single wire.

In the ultrasonic bonding device 1 according to the embodiment, the partition areas 22, 23 adjacent to each other in the width direction Y have partition widths L of the same length in the width direction Y, but this is not limited to this, and the partition areas may have partition widths L1, L2 of different lengths in the width direction Y, as shown in FIG. 7.

In addition, in the ultrasonic bonding device 1 according to the embodiment, the partitioned regions 22, 23 adjacent to each other in the width direction Y are formed so that their surface roughness differs from each other, but this is not limited to this. For example, one of the partitioned regions 22, 23 adjacent to each other in the width direction Y may be the vibration surface 13 itself, and the other may be coated with a metal film having a friction coefficient different from that of the vibration surface 13. In the ultrasonic bonding device 1, the friction coefficients are different between the partitioned regions 22, 23 by coating one of the partitioned regions 22, 23 adjacent to each other in the width direction Y with a metal film having a friction coefficient different from that of the vibration surface 13. As a result, the frictional forces acting on the partitioned regions 22, 23 adjacent to each other in the width direction Y due to contact with the wire W11 at the core wire exposed portion W1a can be relatively different from each other alternately along the width direction Y. Such a metal film is preferably composed of a metal material such as titanium (Ti), vanadium (V), nickel (Ni), molybdenum (Mo), or a compound thereof.

In addition, in the ultrasonic bonding device 1 according to the embodiment, the partitioned regions 22, 23 adjacent to each other in the width direction Y are formed so that the height of the protrusions 24 on the surfaces is the same, but this is not limited to this, and the multiple protrusions 24 formed on the vibration surface 21 may be omitted.

In addition, the ultrasonic joining device 1 according to the embodiment may be formed so that the partitioned regions 22, 23 adjacent to each other in the width direction Y have different heights of the protrusions 24 on their surfaces. In this case, even if the surface roughness of the partitioned regions 22, 23 adjacent to each other in the width direction Y is the same, it is possible to make the frictional forces of the partitioned regions 22, 23 acting due to contact with the wire W11 in the exposed core wire portion W1a relatively different from each other alternately along the width direction Y.

In addition, in the ultrasonic bonding device 1 according to the above embodiment, the partitioned regions 22, 23 adjacent to each other in the width direction Y are formed so that the contact areas T1, T2 with the wire W11 are the same (see FIG. 5), but this is not limited thereto and may be formed so that they are different from each other. For example, as an ultrasonic bonding device 1 according to a modified example of the above embodiment, when the partitioned regions 22A, 23A adjacent to each other in the width direction Y have the same partition width L, multiple recesses 25 may be formed in one of the partitioned regions 22, 23 to make the contact areas T1, T2 with the wire W11 different from each other (see FIG. 7). The recesses 25 are, for example, grooves extending along the axial direction X and formed from the vibration surface 21 toward the inside of the vibration member 13, as shown in FIG. In the ultrasonic bonding device 1, the partitioned regions 22A, 23A adjacent to each other in the width direction Y are formed so that the contact areas T1, T2 with the wire W11 are different from each other. In this way, the ultrasonic bonding device 1 makes the contact areas T1, T2 with the wire W11 of the partitioned regions 22A, 23A adjacent to each other in the width direction Y different, thereby reducing the frictional force between the partitioned regions 22A and the wire W11 of the partitioned region 23A, making it possible to relatively differ the frictional force between the partitioned regions 22A, 23A.

In addition, the ultrasonic joining device 1 according to the above embodiment and modified example forms a single-wire portion W1b for the core exposed portion W1a of one electric wire W by the processing device 2, but is not limited to this. For example, as an ultrasonic joining device 1 according to another modified example of the above embodiment, the processing device 2 may be configured to form a single-wire portion W1b for a plurality of core exposed portions W1a formed by bundling a plurality of electric wires W. In this case, the ultrasonic joining device 1 includes a processing device 2, a pair of holding members 11 arranged opposite to each other in the width direction Y and clamping the plurality of core exposed portions W1a in the width direction Y, and a pressure member 12 and a vibration member 13 arranged opposite to each other in the height direction Z, clamping the plurality of core exposed portions W1a in the height direction Z, and applying ultrasonic vibration to the plurality of core exposed portions W1a to vibrate them in the axial direction X and join the strands W11 together. The vibration member 13 has a vibration surface 21 having multiple partitioned regions 22, 23 partitioned along the width direction Y by a partition width L corresponding to the outer diameter S of the wire W11. The multiple partitioned regions 22, 23 have relatively different frictional forces acting due to contact with the wire W11 at the multiple exposed core wire portions W1a alternately along the width direction Y. As a result, the ultrasonic joining device 1 according to the other modified example can improve the joining of the exposed core wire portions W1a of the multiple electric wires W and the joining of the multiple wires W11 in the width direction Y, thereby improving the joining of the wires W11 when the core wire W1, which is a bundle of multiple wires W11, is made into a single wire.

REFERENCE SIGNS LIST 1 ultrasonic bonding device 2 processing device 11 holding member 12 pressure member 13 vibration member 15 accommodation space 21 vibration surface 22, 23 partitioned area 24 convex portion 25 concave portion W electric wire W1 core wire W11 strand W1a exposed core wire portion W1b single wire portion W2 insulating coating

Claims (5)

The electric wire has a core wire made of a plurality of conductive wires extending along an axial direction, and an insulating coating covering the core wire with an end of the core wire exposed as a core wire exposed portion, and the electric wire is provided with a processing device for forming a single wire portion by solidifying the plurality of wires in the core wire exposed portion,
The processing device includes:
a pair of holding members arranged opposite to each other in a width direction perpendicular to the axial direction and holding the exposed core portion in the width direction;
a pressure member and a vibration member that are disposed opposite to each other in a height direction perpendicular to the axial direction and the width direction, hold the exposed core portion in the height direction, and apply ultrasonic vibration to the exposed core portion to vibrate it in the axial direction to join the strands of wire together,
The vibration member is
the vibration member and the pressure member have a vibration surface facing the exposed core portion in the height direction in a clamping state in which the exposed core portion is clamped in the height direction,
The vibration surface is
a plurality of partition areas that are in contact with the exposed core portion in the clamped state and that are partitioned along the width direction by partition widths corresponding to outer diameters of the wires,
The plurality of partitioned regions include
the frictional forces acting due to contact between the exposed core wire portions and the wires vary relatively alternately along the width direction. The vibration surface is
The ultrasonic joining device according to claim 1 , wherein a partition width of the partition region satisfies the following relationship: outer diameter of the strand≦partition width≦outer diameter of the exposed core portion/2. The ultrasonic bonding device according to claim 1 or 2, wherein the partitioned regions adjacent to each other in the width direction are formed to have different surface roughnesses. The ultrasonic bonding device according to claim 1 or 2, wherein the partitioned regions adjacent to each other in the width direction are formed so that the heights of the protrusions on the surfaces of the partitioned regions are different from each other. The ultrasonic bonding device according to claim 1 or 2, wherein the partitioned regions adjacent to each other in the width direction are formed to have different contact areas with the wire.

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